2015 Is Now Earth’s Hottest Year on Record, and My, What a Year It Was

An Indian man walks across the dried-out bed of Lake Ahmad Sar in Ahmedabad, India, during a heat wave in May 2015.

Photo by Sam Panthaky/AFP/Getty Images

On Wednesday, scientists from the National Oceanic and Atmospheric Administration and NASA announced what everyone already knew: There’s never been a year like 2015, now officially our planet’s warmest year on record.

The record was broken in spectacular fashion. According to NOAA’s data, last year’s global temperature topped the previous record (2014) by the widest margin ever—breaking the record for how much it was breaking the record by. There’s no other conclusion to draw from this kind of data: Our planet is getting warmer due to climate change, and that warm trend is accelerating.

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And, as it turns out, December 2015—which featured Christmas Eve barbeques and freakishly warm temperatures in the 70s up and down the East Coast—was the warmest of all. In both NOAA and NASA datasets, which use slightly different independent methods to compile temperature information, December 2015 was the most anomalously warm month of any month in any year on record—the first time any single month has reached the two-degree Fahrenheit threshold above pre-industrial levels. The record-setting data confirms a third global temperature dataset from Japan, which was released last week.

New developments in climate science last year demonstrated that a lot more extreme events like these will occur in the years ahead. In October, NOAA announced that a worldwide coral bleaching event had begun, and in July, James Hansen shocked the scientific community with a sea-level rise forecast for the coming decades far beyond what had previously been considered possible.

Though official weather records only date back to the late 1800s, there’s ample evidence that 2015 was probably the warmest year over a much longer stretch of time, at least since the invention of agriculture more than 10,000 years ago. There’s also building evidence that the current supercharged El Niño—itself now the strongest ever measured—may have jumpstarted a decadeslong period of accelerated global warming, boosting the longer-term signal from humanity’s habit of burning fossil fuels.

“NASA has been talking about the existence of global warming in public since 1988,” NASA’s lead climate scientist Gavin Schmidt told the Washington Post. “1988 was also a record warm year for the time. Just so that people understand, it is now 23rd in the rankings.”

In a warming world, even a year as crazy as 2015 won’t hold the all-time record very long. In fact, the still-strong El Niño will very likely ensure that 2016 will challenge 2015 for the top spot.

“In previous El Niño years, they peak in the wintertime … [and] the warmest temperatures are in the subsequent year,” NOAA’s Tom Karl told the Washington Post. “If 2016 continues like we’ve seen in the past, that would suggest 2016 is going to be very close to a record or even a new record.”